of trees, tree-rings. Main principle of dendrochronology is cross-dating. Dendrochronologists
analyze tree-rings by their common growth behaviour and, as initial step
analyses, cross-match the wide and narrow tree-rings among the array of
samples. One tree-ring chronology consists of tens or
hundreds, even thousands, of
individual tree-ring series of the
species from a given region. Series are
averaged annually to form reliable records of past growth
to cross-dating, tree-ring chronology becomes dated with absolute accuracy.
and environmental factors influence the growth of tree-rings from
time-scales. This creates possibility to date the past climatic
and environmental events with
possible precision of all geological
tree-ring oriented research at the
Department of Geology includes wide spectrum of dendrochronological
study of subfossil tree-rings has for long been the speciality of the
group. Scots pine (Pinus sylvestris
L.) megafossils remain preserved in the bottom sediments
small lakes, peat bogs
and as dead standing trees (snags). Additional tree-ring material can
obtained from historical buildings. Theory of cross-dating is a key to
composite chronologies from living,
historical and subfossil tree-rings. Megafossil
collection from northernmost Lapland
covers the past 76
centuries being one of the longest continuous tree-ring
chronologies in the world. At the same time,
this chronology is probably the
longest absolutely dated and annually resolved temperature proxy
collection has been made in intensive collaboration with the Finnish
Institute and SAIMA Centre for Environmental Sciences.
The basis of our dendrochronological
is the compound interpretation of living tree and subfossil
variability and factors behind their behaviour. The research can be
divided into several
different subfields as follows:
constructing new tree-ring chronologies
studying the relationships between tree-rings and climate
studying the relationships between tree-rings and ecological factors
reconstructing the past climates using tree-ring chronologies
interpreting the past environments from tree-ring based records
analysis is used in all aforementioned (1-5) subfields of
Students aiming for
dendrochronological thesis (Bachelor, Master, Licentiate or
Ph.D.) should familiarize
himself/herself with at
least the basic concepts of time-series analysis!
Recent research has
been carried out mostly by Emeritus Professor
Holopainen and Marc
the Biogeoscience Institute of the University of
Please contact one of us
for further information!
processes and large-scale climate relationships in northern coniferous
Marc Macias Fauria
of past climates from documentary and natural sources
the 18th century"
tree-ring chronologies as records of climate variability in Finland"
Tree-ring dating in Estonia"
Essential text-books about
tree-ring for students
Vaganov E.A., Hughes M.K. & Shashkin A.V. 2006:
Growth Dynamics of Conifer Tree Rings: Images of Past and Future
Environments. Ecological Studies 183: 354 pp.
Cook E.R. &
(Editors) 1990: Methods of
Dendrochronology. Kluwer Academic Publishers, 394 pp.
Hughes M.K., Kelly
P.M., Pilcher J.R., Lamarche
V.C., Jr. (Editors) 1982: Climate from tree rings. Cambridge University
Press, 223 pp.
Fritts H.C. 1976:
Tree Rings and
Academic Press, 567 pp.